This is a multidisciplinary program within the Department of Medical Viral Oncology using the integrated contributions of existing groups and new laboratories in order to describe mechanisms of malignant cellular transformation and find means for its control. Our approach to this goal depends heavily upon studying the control of viral expression because viruses can provide a powerful tool for uncovering fundamental cellular processes. This goal by four routes, corresponding to the following segments: the first segment describes means to develop selective viral inhibitors, the second, means to determine how a potentially oncogenic DNA virus may accomplish genetic transfer between cells, the third, means to describe physiological mechanisms which modulate the expression of potentially oncogenic RNA viruses, and the fourth, means to examine some of the events during an antitumor immunological response. These projects range from the molecular and subcellular levels to the cellular and organismic levels, elucidate physiological and pharmacological mechanisms for viral inhibition, and yield knowledge of fundamental processes and knowledge suggesting clinical application. Since the program combines the efforts of scientists trained in biochemistry, cell biology, immunology, molecular biology, pharmacology, and virology, the intellectual perspectives available and the methods used correspondingly diverse. This interaction among these disciplines will yield new approaches to problems in expression of genetic information, in mechanisms of malignant transformation and in therapy of cancer.